Lubricant



Patented 3, 1939 UNITED STATES PATENT OFFICE 2,142,219 LUBRICANT Erich M. Stetl'en, Berlin, Germany, assignor, by mesne assignments, of three-fourths to Tide Water Associated Oil Company, New York. N. Y., a corporation of Delaware No Drawing, Application August 1, 1933, Serial No. 683,169. Renewed September 26, 1938 .140laims.

At the present time most high grade lubricating oils are produced from paraffin or mixed base crude oils. These crude oils contain considerable amounts of waxy materials which have boiling .0. points in the same range as the lubricating oils. In producing lubricating oils two types of stocks are prepared from the crude oil. These stocks are overhead distillates and residual oils, that is, oils which have not been vaporized. Both stocks contain waxy hydrocarbons in amounts sufilcient forms small crystals and is known as the amorphous type. It is a relatively simple matter to remove large crystalline waxes by fltration, and

v thisis done in ordinary commercial practice by means of filter presses. In this step the bulk of the wax is removed. 'However, sufficient wax, predominantly of the amorphous kind, remains in the oil to give high A. S. T. M. pour-points. It is very diflicult to remove this type of wax by filtration, since the small crystals do not form rigid and porous filter cakes, in consequence of. which the filtration rates are very low. It is possible to remove amorphous wax by filtration, in

40 dilution, with a filter-aid, but again low filtering,

rates usually make the operation an expensive one.

The concentration of the amorphous wax in such lubricating distillates is low, being approximately 2% of the oil, while the crystalline wax may be approximately 10% of the oil. This small amount of amorphous wax is not sufficient to affect the lubricating qualities of the oil. However, at low temperatures sufllcient crystals will come out-of solution in the oil to give the lubricant an extremely high resistance to flow at low temperatures. This lack of fluidity is indicated by the A. S. T. M. pour-point method. In this test the pour-point is taken as the temperature at which oil will no longer flow whenan nudist tributed body of this oil has been cooled slowly. It can be readily appreciated that in such a test the crystals formedhave-ample opportunity to grow and interlock, thus forming a relatively rigid structure through the oil. It.,is generally 5 known that if at the pour-point temperature the crystal structure is broken by stirring, the oil will again flow reasonably freely, indicating that the mere amount of wax present is not sufficient to cause lack of fluidity. Thus, if the amorphous 10 wax on separation can be caused to form still smaller crystals which will not interlock and give this rigid structure at low temperatures, the oil will be a great deal more satisfactory, particularly for use in. cold weather in, automobiles, for exl5 ample.

A similar problem in wax removal occurs in the treatment of lubricating oils made from residual oils. Practically all or the waxes contained in such oils are of the amorphous type, and conse- 2o quently the methods of removal are not by filtration, but settling or centrifuging in solution. It is a relatively easy matter to remove the bulk of the wax, but in order to remove the last traces and insure fluidity at temperatures in the order 25 of 0 to 10 F., exceptionally low separating temperatures are necessary.

I have discovered that the fluidity oi' wax-containing oils at low temperatures may be insured by the addition of a new composition of matter 30 of great stability, so that this fluidity will. be maintained after long periods in storage or after the lubricating oil has been exposed to high temperatures.

In orderto prepare this composition of matter, 35 I dissolve a rubber material in a low boiling min= er'al oil fraction, such as solvent naphtha. A. catalyst such as anhydrous aluminum chlorid is added at room temperature under agitation and the mixture .is kept as. these conditions for. ap- 4o proximately 16-24 hours. The temperature then isslowly raised to between and F. for about three hours to complete the reaction. The products are allowed to cool and to settle. The

sludge is separated and a synthetic product is 45 obtained, dissolved in the solvent mineral oil frac tion. After neutralizing the solution by washing 7 with lye and water for example, the. synthetic product may be recovered by distilling oil. the solvent. Additional products may be recovered from 50 the alum'inous sludge by admixing the same with water in the presence of a solvent, washing the solution with lye andwater and distilling of! the solvent.

preparation of these products are crepe rubber, caoutchouc, vulcanized rubber, gutta percha and balata. The products obtained from gutta percha and balata have pour-point depressing properties, though not as pronounced as those of the products made from the other rubbers.

Example I To 15 litres of solvent naphtha, having a boiling range of ZOO/350 F. is added 680 grams of crepe rubber. The mixture is heated under agitation to 130 F. for three hours and allowed to cool. 200 grams of anhydrous aluminum chlorid are slowly added at room temperature and'allowed to react for about 16 hours. The temperature is then brought slowly to between 160 and 175 F. and maintained atthis point for approximately three hours. Considerable volumes of hydrogen chlorid are formed. The final mixture is allowed to cool and the naphtha solution is withdrawn from the sludge. This solution is then purified by washing with an alkaline solution and finally with water. The solution may further be purified by filtration over fullers earth or similar adsorptive material to improve the demulsibility of the final lubricant, and is finally subjected to distillation for the removal of the solvent naphtha. The synthetic product is obtained as a residue. It has a yellow tored color and proves to have a remarkable stability when brought into contact with concentrated sulphuric acid.

It has the following inspection:

Gravity, A, P. I 23 Saybolt viscosity at 100 F 680 sec. Saybolt viscosity at 210 F 96 sec.

An additional 10 litres of solvent naphtha and 2 litres of water are added to the aluminous sludge and the mixture is agitated for several hours. After settling, the naphtha solution is withdrawn and purified in the manner described above. A distillation residue is obtained as product which has a darker color than the first product and an extremely high viscosity.

The first and the second residual products are then blended with lubricating oil in proportions of 2% by weight of the synthetic product. The A. S. T. M. tests of the original oil and of the blends follow:

500 grams of caoutchouc are introduced into 10 litres of naphtha. The mixture is agitated until a homogeneous mixture results. 100 grams of anhydrous aluminum chlorid are added at a temperature of about 100 F. The mixture is kept for 3 hours at 120 F. and for additional 2 hours at 170 F. and 2 litres of water are then slowly added. The mixture is finally allowed to cool. The naphtha solution is withdrawn and,

' reduced by fire and steam to about 2 litres. 500

grams of a mineral lubricating oil are added for the purpose of increasing the fluidity or the material, the solution is filtered through a Floridin clay and finally distilled to remove the naphtha.

A residual product is obtained which resembles a very viscous lubricating oil having a viscosity at 210 F. of about 350 Saybolt seconds. The lubricating oil added had a viscosity at 210 F. of 47 Saybolt seconds.

The oil thus obtained was blended with a lubricating oil in proportions of 2% by weight of the synthetic product prepared. The tests of the original oil and of the blend follow:

O i Bleriigled rig na w Tests oil synthetic product Gravity, A. P. T 29. 7 29. Flash point 410 F. 410 F. Saybolt viscosity at 100 F 191 sec. 203 sec. Saybolt viscosity at 210 F 47 Sec. 48 see. Pour-point +20 F. -5 F. Color, A. S. T. M 3% 4% Carbon residue 05 04 uct is satisfactory, and for the heavier grades of oil about 3%. Some lowering of pour-point results from addition of the products as low as .05%-1%.

When the products are blended with mineral lubricating oils in proportions larger than about two or three per cent., they have the advantageous eilect of reducing the slope of the viscosity-temperature curve of the oil.

The synthetic materials described above may be regarded as isomerization products of rubber materials. As evidenced by their resistance to the action of sulphuric acid, they are highly stable. Such a quality is of extreme value when the products are to be used in motor oils, since the pour-point, as has been found by actual test, will be maintained at or near the original even after the oil has been exposed to high temperature for a considerable length of time.

It is possible to modify, the product obtained by manufacturing it in the presence of chlorinated hydrocarbons. In such cases, it is believed that, in addition to the formation of polymerized rubber compounds, a certain lesser amount of condensation of the hydrocarbons on the rubber occurs, and possibly even some polymerization of the chlorinated hydrocarbons themselves. In any event the reactions are extremely complex and products having the same property of reducing pour-points as those described above are obtained, differing only in that their lesser viscosity makes them resemble lubricating oils to a greater extent.

The chlorinated hydrocarbons that are used in the preparation of these modified rubber conversion products may be classed as aliphatic hydrocarbons, though this term is not to be understood as caiiing for pure aliphatic materials, since mineral oils predominantly aliphatic usually contain some ring compounds.

For this purpose a mineral oil hydrocarbon, such as a fixed gas, a gas oil, or a non-viscous neutral oil is chlorinated. A rubber material, such as crepe rubber, caoutchouc, or vulcanized rubber, is dissolved in a low boiling solvent such as solvent naphtha. The chlorinated hydrocarbon is added and anhydrous aluminum chloride is introduced into the mixture of rubber, chlorinated hydrocarbon, and solvent. As the reaction occurs, the temperature rises and hydrogen chloride is evolved. A solution results from which the stable products can be recovered by washing with lye and water and removing the solvent by distillation.

Several examples of the production of these products follow, from which the reaction conditions, the ratio of initial materials used in the aluminum chloride conversion step and the characteristics and effects of the products obtained can be seen. 1

- Example III A gas oil obtained from an East Texas crude, having a gravity of 37 A. P. I., an initial boiling point of 478 F. and a final boiling point of 637 F. is chlorinated by passing chlorine through it at a temperature below 200 F. The chlorination is discontinued when it is found that the oil contains about 14% chlorine by weight. A solvent naphtha with 200/350 F. boiling range, which has been purified by treating with-anhydrous aluminum chloride, is added to 500 grams oi? crepe rubber. The mixture of rubber and solvent is heated on a reflux condenser equipped with a water trap until all the moisture has been driven off and is then allowed to cool. 1500 grams of the chlorinated gas oil are introduced into the rubber and solvent mixture and 200 grams of anhydrous aluminum chloride are slowly added at room temperature under agitation. The temperature rises to about 120 F. and considerable 'volumes of hydrogen chloride are evolved. At the end of several hours the temperature is raised to about 190 F. and 220 F. Steam is introduced into the resulting solution, vaporizing part of the solvent. When about half of the solvent has been distilled, the distillation is discontinued and the residual liquid is separated from the sludge. The liquid is washed with a lye solution, till neutral, and subjected to distillation. A residual product is obtained having a high viscosity and the appearance of a lubricating oil. A blend of 2% by weight of the product with a lubricating oil is prepared. The tests on the original oil and the blend follow:

Ori inal oil Blend Gravity, A. P. I 29. 6 29. 2 Flash point 420 F. 420 F. Saybolt viscosity at 100 F. 187 sec. 212 sec. Saybolt viscosity at 210 F 47 sec. 49 sec. Pour-point +20 F. -l5 F.

Example IV for about sixteen hours, whereafter the temperature is raised to 160 F. for a period of two hours. A ter cooling, 1 litre of water is added under a81- tation. The sludge is then allowed to settle and the naphtha solution is withdrawn for purification and redistillation as shown above. A residual oil is obtained showing the following inspection.

Gravity, A. P. I 23 Saybolt viscosity at F 3600 see. Saybalt viscosity at 210 F 165 sec.

A blend is prepared using two parts by weight of the synthetic oil and 100 parts by weight of a lubricating oil. The tests of the original lubricating oil and of the blend are shown below:

Original on Blend Gravity, A. I. I .6 .5 Flash point 420 F. 420 F. Saybolt viscosity at 100 187 sec. 196 sec. Saybolt viscosity at 210 F 47 sec. 48 sec. Pour-point +20 F. 5 F. Color, A. S. T. M 3% 4% Example V 30 litres of solvent naphtha having a boiling range of 200 to 350 F. are heated to about F. During agitation, 2000 grams of crepe, rubber are introduced. At the end of three hours the temperture is raised sufliciently to remove all the moisture by distilling oil part of the solvent naphtha. 3000 grams of ethylene dichloride are added to the resulting mixture, which has been cooled. At room temperature 450 grams of an- Gravity, A. P. I 21 Saybolt viscosity at 100 F 1350 sec. Saybolt viscosity at 210 F 117 sec.

Color, A. S. T. M 3 A blend is prepared consisting of two parts by weight of the above oil and 100 parts by weight of a lubricating oil. The tests of the original lubricating oil and the blend are shown below:

Original on Blend Gravity, A. P. I 29.7 29. 6 Flash 420 F. 420 Saybolt viscosity at 100 F 192 sec. 206 sec. Saybolt viscosity at 210 F 47 sec. 49 sec. Pour-point +20 F. 5 F. Color. A. S. T. M 3% 3% An additional blend is made consisting of three parts by weight of the product prepared above and 100 parts by weight of a heavy lubricating oil. The tests of the heavy lubricating oil and of the blend follow:

Original on Blend 7 Gravity, A. P. I 26.0 25.7 Flash 525 F.- 540 F. Saybolt viscosity at 100 F 2288 see. 7/405 sec. Saybolt viscosity at 2l0 F 148 sec. sec. Pour-point +25 F. +l0 F. Color, A S. 'I. M 7% 7% Gravity, A. P. I 19 Saybolt viscosity at 100 F 11000 sec. Saybolt viscosity at 210 F 346 sec. Pour-point 15/20 F. Color, A. S. T. M 5

A blend is prepared consisting of two parts by weight of this blend, and 100 parts by weight of a lubricating oil. The inspections of the original lubricating oil and of the final blend follow:

Original on Blend Gravity, A. P. I 29. 6 29. 3 Flash 420 F 425 F. Saybolt viscosity at 100 F 187 sec 223 sec. Saybolt viscosity at 210 F 47 sec. 52 sec. Pour-point +20 F. l0 F. Color, A. S. T. M 3% 3% I claim:

1. An improved lubricant comprising a blend of a major proportion of a wax-containing viscous hydrocarbon oil and a minor proportion of products obtained by dissolving rubber in a low boiling mineral oil fraction, adding anhydrous aluminum chloride, and effecting a conversion of the rubber with the aid of heat.

2. An improved lubricant comprising a blend of a major proportion of a wax-containing vis-' cous hydrocarbon oil and a minor proportion of products obtained by acting upon rubber, while dissolved in a low boiling mineral oil fraction and in the presence of chlorinated hydrocarbons, with anhydrous aluminum chloride under temperature conditions effective to provide conversion products having pour point lowering properties.

-3. An improved lubricant containing in major proportion a wax-containing viscous hydrocarbon oil and also containing, in minor proportion from about 0.05% to about 5.0% based on the weight of said oil, products derived from the conversion oi a rubber materialv by the action of anhydrous aluminum chloridewith the aid of heat under conditions eifective to impart to said products pour point lowering properties, said lubricant having a pour point on the Fahrenheit scale lower than that of said oil by from about fifteen to about thirty-five degrees.

4. An improved lubricant having as a major constituent a wax-containing viscous hydrocarbon oil and containing, in relatively minor proportion based on the amount of said oil, products obtained by acting upon a rubber material, while in a dissolved phase, with anhydrous aluminum chloride under conditions efiective to produce conversion products of rubber having pour point lowering properties.

5. An improved lubricant having as a major constituent a wax-containing viscous hydrocarbon oil and containing, in relatively minor proportion based on the amount of said oil, an anhydrous aluminum chloride conversion product of rubber characterized by its effectiveness in substantially lowering the pour point of said oil.

6. An improved lubricant having as a major constituent a wax-containing viscous hydrocarbon oil and containing aluminum chloride conversion products of rubber capable of lowering the pour point of said hydrocarbon oil, said products being present in proportions of from about 0.05% to about 5.0% by weight based upon the amount of said hydrocarbon oil.

7. The method of preparing lubricants having as a major constituent a wax-containing viscous hydrocarbon oil, said lubricant having a pour point substantially lower than that of said oil, which comprises blending with said oil a minor proportion of products obtained by dissolving rubber in a low boiling mineral oil fraction, adding anhydrousjaluminumchloride. and efiecting a conversion of the rubber with the aid of heat.

8. The method of preparing lubricants having as a major constituent a wax-containing viscous hydrocarbon oil, said lubricant having a pour point substantially lower than that of said oil, which comprises blending with said oil a minor proportion of products obtained by acting upon a rubber material, while in a dissolved phase, with anhydrous aluminum chloride, and heating to effect a conversion of rubber to products characterized by a p'our point lowering effect upon wax-containing hydrocarbon oils.

9. The method of preparing lubricants having as a major constituent a wax-containing viscous hydrocarbon oil, said lubricant having a pour point substantially lower than that of said oil, which comprises blending with said oil a minor proportion of products obtained by the anhydrous aluminum chloride conversion of a rubber material under conditions efiective to produce conversion products characterized by a pour point lowering effect upon wax-containing hydrocarbon oils.

10. An improved lubricant having as a major constituent a wax-containing viscous hydrocarof rubber and chlorinated hydrocarbons characterized by effectiveness in substantially lowering the pour point of said oil.

12. The method of preparing lubricants having as a major constituent a wax-containing viscous hydrocarbon oil, said lubricant having a pour point substantially lower than that of said oil,

which comprises blending with said oil a minor proportion of products obtained by acting upon a rubber material while in a dissolved phase and in the presence of chlorinated hydrocarbons, with anhydrous aluminum chloride, and heating to effect a conversion to products characterized by a pour point lowering efiecirupon wax-containing hydrocarbon oils.

13. The method of preparing lubricants having as a major constituent a wax-containing viscous hydrocarbonoil, said lubricant having a'pour point .substantially lower than that of said oil,

which comprises blending with said oil a minor proportion of products obtained by the anhy drous aluminum chloride conversion of rubber and chlorinated hydrocarbons under conditions effective to produce conversion products characterized by a pour-point lowering efiect upon wax containing hydrocarbon oils.

14. An improved lubricant comprising a blend ERICH M. S'I'EFFEN.

CERTIFICATE OF CORRECTION.

Patent No.1 2,1L 2,219.

January 5 1959.

' ERICH H. STEFFEN.

It is hereby certified that error appears in the printed specification of the above numberedpatent requiring correction as follows: Page 1, second column, line L O, for the word "as" read at; page 2, second column, line 1 1, for "isomerization" read polymerization; and that the. said Letters Patent should be readwith this correction therein that-the same may conform I to the record ofpthe casein the Patent Office,

Signed and sealed this 21st day of February, A. D. 1959,

(Seal) Henry Van Arsdale. Acting Commissioner of Patents. 

